Stable selenium sulphide and method for its preparation



Pateniecllviay 24, 19 32 Qumran ,Js m

, BIRGER w. NORDLANDERQ'OF SGI-IENECI'ADKiVEWYORK,ASSIGNbR rojennnitfarfnnne V TRIO comranxaooarormrron or vnwxonx i STABLE SELENIUM SULPI-IIIDE H mmusalesemme ma v;

No Drawing.

The present invention is a continuation in part of my cop-ending application Serial No. 82,883, filed January 21, 1926, now Patent $51,711,742, granted May 7 1929, and relates to a stable, chemically active compound of I selenium sulphide and the process ofpreparing the same;

In the above namedcopending application I described a means for detecting mercury do vapor in a gas by the useof selenium sulphide.

In that case I also; set forth several methods r never before been prepared. A few attempts have been m'ade',to my knowledge, toproduce stable selenium sulphide of definite composition, but no satisfactory results were, ob-

tained. For example, it has been found that I .25 when hydrogen sulphide is passed into a solution of selenlous acid, a yellow sol and a pre cipitate of a yellowish red color, having" a lastic consistency are formed together.

omplete reaction does not seem to occur since the solution formed always contains unchanged selenious acid no matter how long the hydrogen sulphide is allowed to act. The

precipitate is very voluminous and much of the acid solution is adsorbed. In this plastic 5 form the precipitate is very unstable, especially when heated or exposed to light and is" chemically not active. 'i

, I have succeeded in preparing selenium sulphide of a definite composition corre sponding'to the formula Ses which is stable chemically and chemically extremely active.

Such a product has been kept for years without losing its activity. r

' One method of preparing this compound is as follows A Application filed March 28.21929. Seria1"ZNo. 350; 83 i. a

ing about .100 milligrams of aluminum per. literiis saturated with .hydrggenxsulphi'de .at. room -temperature,preferably in afiask-athat is,partly .closed ingorder'gto .retain an:.atmosg phere.of.the,g-as,abovewtheliquidarrdgthhs .p mete b pti by thee u i ndwii s' e the reaction. igorousmechanical'.-stirring m I'is also,desirable-fonthe'samepnrp ose. ..W hi1e continuing; the current. (ifhydr gensulphiQe,a normal .;selenious .acid solution -.is 'slowly Y a I added, delivering below thesunface ofthe liquid in;,the' fiask. .At firstv anyellowishtspl is 7 formed whrch merysoon;astheconcentra on vvincreases;1s' converted sto v,a yellowiflocelilent as .precipitatewhichsreadily separatesoua frqm Y the solution. A moderate temporaryexcess o f thel, acid .will ,form. -a .sol which Quickly; zclears.up if-thegaddition is stoppedkforthe '.time. ,1he operation {.s'houldbe..carefully gg watchedto keep thehydrogen sulpl1ideinex-,: V .cess. The .aluminirm zchloride acts as a co 7 agulant .for the gsulphide. v i 1 Other. coagi lants ay b a r h f a e punpqeegi nda a example, .bariumlchloride may.be mentionedsi g f .The reaction-;proceeds guantitat ively accord .ingtotheformrila,

I aniseng-seogssesyeengo Thej precipitate isifilt ered, Washed V i {on a steambathwithoutlturriiiig red.

a In accordance with anotherfmethofl.off ri 'jf paring this compound of selenium'sulphide, sulphurand selenium are m xed together. imam "the proportion 'of 'o1'ie;moleculafr weight of. I"

selenium totwo .inolecularfweights been: V phurfand-the mixtu're heated to atone-5225 QC. A-union takes :place sothat a cherryfrejd melt er selenium sulphide see; is .i'formedts'w Whenfcooled down to roomttemperature "it formshajiblack plastic m'assgplasticin char-i .iaeteiulikezruhber- Itawill retain Lthiscondi- .tionfforseveral-days, butiwill'thenzgradually .go :over :into 1 a zhardibrittle. state qsoathati'it AQsolutionlof aluminum.-chloride.eontain il canbe'ground up to form an "orange red powder with a melting point of about. 100

' C. [This conversion is accelerated by heat and v of time, about half an hour.

if the mass is kept just below the melting point, say about 80 to 90 C.,* a conversion takes place in'a considerably shorter period The plastic form "is inactive but the heat treatment changesit over to-the active iorin. f" Selenium sulphide prepared by eitherof these-methodsis stable and chemically active andis always of definite composition. If,

' in the secondmethod outlined above,other proportions of selenium and sulphur are used,

The term fand'li'g-htand denotesalso that the product of" the present invention 7 is not decomposed by such agenc es but retalnssits composition, "that is' the sulphur 'and selenium remain chemically combined having the composition represented by the formula Ses 'l;

ride, with seleniousacid, and precipitate formed.

, 7. The method ofproducing stable .cheniically active selenium disulphide which consists in treating a solution of hydrogen sulphide containing aluminum chloride asffa coagulant, with selenious' acid, to :precipitate the'selenium sulphide," the hydrogen sulphide being-kept in excess,re'moving the precipitate so formed, washing and drying "the same. i

In witnesswhereofl have'hereunto set my hand this 27th day of Marchy1929. e l BIRGER w, ounnaunna.

separating the i The ter'm "cheniicall'yactive" as applied to i the-selenium sulphide Iproducedfby thepres ent: invention denotesthat the 'compoundis V fireactive che nically with substances with V f'whi'ch ordinary mixtures ofselenium and 3 sulphur or compositions of'selenium' and sulphur not prepared by the methods of the "presentiinvention are --;substantially not refactiver What I 1 claim as --n ew and desire to secure Y by Letters" Patent of the United States, is

- L Stable, chemically" active selenium disulphide. 7: f f

'2. A selenium sulphidehaving the chemical composition represented by the formula l is chemically active to mercury'vapor. 3. A compound consisting of selenium and ,SeSgwhich is stable toilig'htj and heatanjd a i 7' Q sulphur in stable co1nbination',said compound being chemically active and havingthefor i'cally' activeseleniumgdisulphide which comg prises the steps of treating a solution of jmula SeS "l; The method of producing stable, I cheni- "hydro'genjsulphid iuexcess with selenious l jg'l he method of producing stable' selen-f fium "disulphide I which comprises the steps of-iprecipitating'the selenium sulphide with selenious acidl from a solution containing hydrogen sulphide in excess and in the presence of a-coagulant.

G'JThe methQd of producing stable selen- :iun disulphide which comprises the steps of treating a solution of hydrogen sulphide IDVGXCESS anduvhich contains aluminum chlo- 

